Dam constsuction



v. H. cocHRANE DAM CONS TRUCTION 4 SheetswSheet 1 Oct. 6, 1925,

V. H. COHRANE DAM CONSTRUCTION Fiied Feb. 2,.-19225 4 Sheefisheet 3 oct. s, 1925. 1,556,080

V. H. COCHRANE DAM CONSTRUCTION Filed Feb. 2, 1925 4 Sheets-Sheet 4 Patented 0st. 6, 1925s i llNlTED SlTATES VICTOR HUGO COGHRANE, 0F TULSA, 'KLAli-OMA.

DAM CONSTRUCTION.

Application filed February 2, 1923.

To all vuil/710m it may concern.' i

lie it known that l, Vieron I-l. Gooi-Imran, a citizen of the United States, residing at Tulsa, in the county of Tulsa and State of Oklahoma, have invented certain new and useful lmprovements in Dam Constructions, of which the following` is a specification.

rlhis invention relates to improvements in dam constructions.

The primary object of this invention is the provision of an economical and aesthetic multiple arch dam construction, embodying;` features which render the same safe under varying` conditions.

A further object of this invention is the provision of a multiple arch dani designed and constructed to remedy the defects genen ally found in arch dams, havinsil particular regard to durability and flexibility of arrangement, and which may safely respond to various circumstances, such as shrinkage, elasticity of material, and changes in tempeinture without undue stress in parts or liability of fracture.

A further object of this invention is the provision of a simple and economical means of finishingl the top of a multiple arch dam. which does away with the inherent weaknesses in ordinary arch damsand reduces the arch stresses and ditliculties at this portion of the dam to a minimum. i

A further ohject of this invention is the provision of a multiple arch dam, in which the shape, thickness, and other dimensions of the arches are particularly adapted for :'Jupporting the load placed thereon at varions levels below the water surface.

fr further object of this invention is the provision of a novel type of individually complete pier for niultiple arch dams, which stable in construction, and economical.

fi further object of this invention is the provision of an arch for dam constructions, which einliiodies a flexible joint permitting of desired arch movements and deflections, incident to varialiile loads and other circumstances.

Other ohiects and advantages of this invention will he apparent during; the course of the following detailed description.

ln the acconipanyingl drawings, forming part this spcciiication, and wherein sin- Seral No. 616,531.

ilar reference characters designate correspondingl parts throughout the several views.

Figure l is an elevation of the improved multiple arch dam, looking' down stream.

Figure 2 is an elevation of a portion of the improved multiple arch dam, looking upstream.

Figure 3 is a transverse cross sectional -iew, taken substantially on the line 3-3 of Figure Figure l is a plan view of a portion of the improved multiple arch dam.

Figure t) isa cross sectional view, taken suhstantially on the line 5 5 of Figure a.

Figure ti is a transverse cross sectional view, talren substantially on the line 6 6 of Figure o.

Figure i is an enlarged transverse cross sectional. view, taken substantially on the line 7H? of F igure 5, showingl certain features of arch design.

Figure tu is an enlarged fragmentary cross sectional view, taken througha joint of an arch of the improved dam construction, showingl the novel joint details.

Figure 9 is an enlarged fragmentary cross sectional view, taken substantially on the line 9-9 of Figure 8.

Figure 10 is an enlarged fragmentary cross sectional view, showingl a modified type of joint for the arches of the improved dam.

Figure ll is a fragmentary cross sectional view, through the type of dam illustrated in F igure 5, showing` the addition of a parapet thereto.

Figure ft2-'is a frao'inentary cross sectional view, showing a dam construction similar to that illustrated .in Figure 5, with the ad dition of a wall thereto, to increase the height of the dam.

Figure i3 is an upstream fragmentary elevation of the improved dani construction, showing` the provision of an overflow spillway in an arch thereof.

Figure lll is a transverse cross sectional view, taken substantially on the line lll- 14 of Figure 13.

Figure lois a fragmentary plan view of the improved dam construction illustrated in Figure 13.

Figure 16 is a transverse cross sectional `iew, taken through an arch dam constructed in accordance with features of this invention and embodying a siphonic spillway.

In the drawings, wherein for the purpose of illustration are shown certain embodiments of this invention, the letter A generally designates the improved dam construction, which preferably includes novel supporting piers B; novel arches C; and a novel closure wall D.

In the construction of piers for multiple arch dams, the practice heretofore has been that of providing relatively narrow piers or buttrcsses which in most instances are connected by tie rods or girders to prevent buckling or collapse of the same. This con struction does not prove entirely satisfactory, on account of the liability of accidental failure of the same, so that in case one arch and butti-ess should collapse, the entire series of arches will fail. To do away with this defect of construction, the improved pier B has been provided, which is simple and economical in design and may bc made with any desired degree of stability. The improved pier B is preferably of concrete or analogous cementitious material, and consists essentially of side walls 17 the rear or arch wall 18; the forward supporting wall 19; and transverse brace 'alls 20. The side walls 17 and the arch receiving wall 18, are of monolithic construction; the wall 18, of course, being inclined at any desired degree. To provide a very stable connection of the top wall or slab 1S with the side walls 17, it is preferred to provide the fillets Q9 at the juncture of said side walls with the wall 18, which face within the space provided intermediate the side walls 17. As the top or arch wall 18 is subject to direct compression incident to the thrust of arches supported thereby, and also to iexure incident to its own weight and the superposed water load, it is preferred that the side walls 17 increase in thickness from the downstream end of the pier, toward the upstream end. In other' words, as is illustrated in Figure G of the drawings, the side walls 17 increase uniformly in thickness from the downstream supporting wall 19 toward the arch supporting wall 18. Any number of transverse walls 20 may be provided, which may be integrally formed at right angles to the side walls 17 and with the arch wall 1S. The downstream wall 19 of the pier B, may likewise be integral with the walls 17, as to seal the spaces intermediate the side walls 17. If desired, the side walls 17 and in fact, any of the pier walls may be provided with enlarged footings embedded in the bed rock.

It is obvious that the pier B may be given any desired degree of lateral stability, simply by increasing the transverse width and spacing of' the walls 17. Thus, the pier can be designed to carry the thrust of the unloaded arch on one side only, or can be made. stable under full water load in case of the failure of an adjacent arch. Any degree or type of reinforcement may bc provided. This type of pier construction lends itselfI readily to dams which are. curved in plan, and in this case it will be necessary to build the side walls 17 at intersecting planes instead of parallel relation, as is illustrated in Figure (3 of tl e drawings.

Referring to the improved arch the same preferably includes the base portion upper or major arch portion 2H; said portions 30 and 31 being connected by an improved joint construction 32, as to permit some degree of movement of the arch pox tion 31 with respect to the portion 3l() or vice versa.

The arches of multiple arch dams are especially .susceptible of slieht movements, which though small are essential, and it is extremely important that provision he made in the design and construction of the arches for such, in so tar as the association ol" the same with respect to piers and their foundations is concerned. Thus, an arch under load is shortened to a certain extent, owing to the elasticity of the masonry, causing the arch to defiect somewhat; this deflection being greatest at the crown and decreasing to* waid the ends. A .similar deflection is produced by shrinkage of the concrete, and by shortening of the arch incident to fall in temperature. On the other hand, increases of temperature or swelling of the concrete cause the arch to rise, so to speak, in the direction of the impounded water. In arch constructions heretofore provided no provision has been made at the base o t the arch as to permit sufficient arch action to prevent internal strains. It is well known that n ar the bottom of the arch, the proper degree of movement is prevented by the bed rock on which the masonry is supported. so that proper deflection of the arch is almost entirely prevented at the base of the arch, and more or less impeded for considerable distance upwardly from the bed rock. As a consequence, the lower portion of the arch acts like a cantilever beam in supporting`- the load which cannot be sustained by arch action. Unless this cantilever portion, so called, is heavily reinforced, and anchored to the bed rock, cracks develop on the upstream side of the arch. 0n the other hand. if the reinforcement and anchorage metal are suHiciently heavy to prevent crackin g ol'V the concrete, the masonry may be so highly stressed as to require thickening near the bed rock level. This thickening in turn aggravates the original. difficulty, since the cantilever is now stiffer and consequentlysustains an augmented load. .\n important object effected by the iinproved arch, which l'lO utilizes the novel joint construction 32, is to insure the proper larch action down to a suitlahle or predetermined point, and below that a definitely determinable amount et cantilever action, requiring;l much less reinforcement and masonry than Ifor the monolithic arch construction heretofore provided.

Referring to the improved joint 82, which is illustrated in the various views oit the drawings, and in enlarged section in Figure 8, the saine extends t 'ansversely across the arch C, intermediate the racing surfaces of the arch portions 30 and 3l, and terminating at its ends in spaced relation adjacent the sj'nfinging edges 35 ot the arch. The plane ot the joint 32 is substantially at right angles to the axis ot the arch, and is not carried entirely across the arch, since there is very little, if any, movement which taires place adjacent the springing portions ot the arch, so that the hase and major portions 30 and 81 of the improved arch C may he constructed integrally outwardly 'from the ends of the joint 32 to the .springing` edges 35 or the arch.

Referring to the improved joint 32 is illustrated in .Figure 8 of the drawings, and according` to the process of constructing the saine, the hase 30 is first built with siiitable reinforcing;` metal 37 embedded therein, and the V-shaped metal diaphragm 38 is anchored at one leg 39 Within the top surface of the base 30, between the extrados l() and -intrados -ll ot the hase arch portion SO, so that the other leg 43 extends upwardly above the top surface of the hase 30, and is adapted for anchorage Within the major arch portion 3l, as will, he .subsequently set forth. It is to he noted that the legs 39 and 4l?) ot the metal diaphragn'i 3S are in diverpinp)` relation toward the entrados oit the arch C, and may be provided with suitable anchoring lugs, as is illustrated in the drffiwings. From the rear ot the diaphragm 38 toward the intrados ot the arch, the abutting,l snriaces of the arch portions 8O and 3l should be'finished smooth, and il' desired, these surfaces may be inished at a slight angle to the direction ot motion of the arch A when defleeting, as is illustrated in Figure 8 of the drawings. These surfaces ot' the arch portions 30 and 3l are substantially intermediate the entrados and intrados oi? the arch, and between said surfaces asphalt or tar paper ll5 is provided, as to etiiect a .slip joint construction, preventing' the concrete ot the arch portions 30 and 3l from adhering); to each other. During the construction ot the arch joint both at the extrados and the intrados ot the arch, recesses are provided in the top of the hase 30. Prior to the pouring` oi the concrete ttor construction oit the arch portion 3l, a recess immediately at the rear ot the diapl'iragm 3S is perinanently tilled with some Water prooiing material, 47, as asphalt, and upon which the concrete for the arch portion 3l may be poured.

The recess at the entrados side of the arch and above the diaphragm 38 is preferably provided with a Wooden or metal iorin, which can be removed when the arch portions 30 and 3l are set. rlhe transx-'erse strip ot-tlexi'ole Waterproof sealing material 5t) may then be poured in this recess, and which in depth entends troni the efrtradori oit the arch to the bottoni oi the diaphragm 33. lhis material 5() is, ot course, placed helio/re the water is permitted to rise to the level oit the joint 32, and may he of any suitable material, such as asphalt. A recess 52 is exposed at the intrados ot the arch, which may be of various shapes, and provided hy collapsible :terms intermediate the arch portions 30 and 3l. rlhis recess 52 is at he downstream side of the arch, and

is lett open until the arch has taken its full load and is under proper temperature conditions, and at which time the saine may be l lilled with groutor concrete as to permanently seal the joint under predetermined conditions olf stress. ln cross section r` the concrete 53 which provides the Vjoint in the recess 52 may be uwt-shaped and suitably anchored 'ny its head within said recess.

leterrin to the modified form oit joint 55, as illustrated in lligure l0 ot the dran?- .ingrs, the nl -shaped diaphragm 56 may he provided therein in manner similar' to the diaphragm 38 above described. The slip joint material 5'?, analogous to the slip joint d5 provided in the preferred form A, may also be included as a part or' the joint rlhe permanent flexible seal 58 may loe disposed immediately at the rear of the diaphragm 56, and the Waterproof sal of asphalt may be provided in exposed relation at the extrados ot the arch. in which the modi'lied joint is provided. At the downstream or intrados side ot the arch embodying` the modified joint 55, the Wedge joint of concrete GO may be provided alter proper arch deflection.

Reit l to the shape et the arch C, the thickness at the crown of the same increases substantially uniformly troni the top ot the arch to the base thereo'l". its the thrust or axial pressure on the arch, incident to the llt) impounded water and arch loads does not Y vary greatly, at any cross section ot the arch troni the center to Jthe sprinp'ingv ends thereoi", it these loads were considered alone. the arch thickness at any cross section might he made uniform from the crown to the springing edges, and as is done in present practice. However, consideration oi" the et'- :tects of arch shortening` shrinkage, and temperature variations show that the arch should have a greater thickness at the ends or adjacent the springing,l edges than at the central portion of the arch. It has been found that it is not necessary to thicken the arch from the central line thereof to predetermined points on each side thereof, near the quarter points of the arch; and from which quarter points toward the springing edges of the arch., said arch may uniformly increase in thickness. As is illustrated in Figure 7, the entrados or' the arch C is preferably formed on a single radius. The intrados ot the arch from th l central line of the arch to the points on each sidethereof, is struck 'from a single radiu. which is concentric with the radius forming the eX- trados of the arch. From the points to the springing edges 35 of the arch C, shorter radii are used, as to increase the thickness` from said points G5 to the springing edges of the arch. These radii upon which the arch C is formed are to be chosen so that the center line or anis of the arch at some secA tion near the base coincides as nearly with the line of pressure as possible. incident to the arch and water loads. Near the top of the arch, it is possible that there may be some eccen'ricity of pressure, but this will be of no consequence, in view of the `fact that the minimum practical. limiting thickness of the arch provides an eX- cess of strength at this point. Since the intrados is ot the same curvature trom the top to the bottom of the arch, the same forms may be used throughout the arch construction.

referring to the improved closure wall D, provided in connection with the dam construction A, the same rests upon the arches C and piers B, and should be properly anchored thereto. This wall D is set in a plane substantially at right angles to the longitudinal axes of the inclined arches C, for several important reasons-lirst, so that the same will be parallel to other parts ot the arch, such as the transverse joint 32, and whereby the dam construction may be simplilied and the stresses best distributed; second, an important feature of this wall is that the same resists the pressure oit' t-he water wholly, or in part, by the weight of the wall itself. As is illustrated in the drawings, the portion of the wall D adjacent the piers B is ot greatest height and thickness, and toward the crowns of the arches C, said wall D decreases in height, so that the wall portion T2 at the crown of the arches is of least depth. This wall may be reinforced, to sustain the water pressure and its own weight, and may be reinforced longitudinally to prevent. cracking under various temperature conditions.

At the top of the wall D, the horizontal toot way 78 may be provided across the dam A. lt desired, a parapet 74 may be built upwardly from the top o't' the wall D in Vertical manner, as is illustrated in Figure mueve@ 11 or" the drawings, upon which a roadway or footway may be provided, as desired. It is contemplated that the dani A may be increased in height, and as is illustrated in Figure 1Q of the drawings, a portion To may be added to the wall D in a vertical plane either at the time of original building of the dam or at any subsequent period thc-reto.

In Figures 13, 14 and 15, an overlhiw type et" the improved dam has been shown. at the top ot' each arch C ot which a spillway 79 is provided, as by breaking the continuity ot the top wall E, so that at the crown portion ot' each arch C, said wall is removed. At the downstream side ot the dani construe tion A, a basin or spillin,"r pool S0 may be provided, for each arch C, which receives the water pouring through the spillway TS) oi its adjacent arch, as to prevent the water from injuring the foundation parts of the arch or dam construction,

As is illustrated in Figure 16, the imn` ved dam is susceptible of having a. siphonic spillway provided therein. This spillway S5 is preferably formed in the downstream wall SG, and the top wall F. .The top portion S7 ot' the spillway S5 is proi led with a bend which communicates with the upstream or impounded water beneath the depending portion 8S ot the dam wall l) g. said portion SS having a transverse opening 89 therein communicating with the rpper portion ot the spillway 85, so that the siphon action may readily take place should the water impounded rise above the transverse opening 89. A shoulder 90 may be provided at the bottom of the spillway, in the downstream wall 86, which restricts the passageway of said spillway. Other 'features of the improved dam embodying the siphonic spillway are substantially the saine as above described.

From the foregoing description of this invention, it is apparent that a multiple arch dam has been provided, the various parts ol which cooperate in overcoming detects which are inherent in present day practice of dani construction.

Various changes in the shape, size, and arrangement ot' parts may be made to the forms of the invention herein shown and described, without departing from the spirit ot the same and the scope of the claims.

I claim:

1. An arch for dam constructions provided with a substantially transverse waterproof joint to permit portions on opposite sides ot' said joint to move relative to each other.

2. An arch for dani constructions substantially subdivided into a major upper portion and a base portion by a waterproof joint pern'iitting relative movement of said arch portion.

An arch for dam constructions proascenso vided with a flexible joint extending sub stantially transversely through the crown portion. thereof.

fl, in arch for dam constructions provided with a flexible joint extending,l substantially transversely through the crown portion thereof, and subdividinn said arch into an upper portion comprising the major portion oif said arch, and a lower base portion.

5. in arch `for dam constructions having a transverse flexible joint at right angles to the axis oi" the arch, the ends of said joint terminating` short of the springing,` ednges of the arch, whereby said arch is divided into portions on opposite sides of the joint capable of safe relative movement.

6. .rin arch for dem constructions providing a foundation portion, a concave-convert arch portion, and a water proof joint connecting said arc-h and foundation portions to permit arch deflection.

7. An arch for dam constructions having a flexible waterproof joint extendingl transversely thereof inwardly from the entrados thereof to permit safe movement of the portions of the arch on opposite sides of said joint. V j

8. A retaining arch of cementitious mate rial including?,` a pfround imbedded base portion, a major arch portion, and a joint intermediate the base and major arch portions which will permit sate defiection of the arch portion with respect to the ground embedded base portion.

9. In a device 't the class described, the coinbination of a supportinp, base, an arch, and waterproof means intermediate the supporting;l and arch permitting' deflection or relative n'iovement of the arch with re. speci'y to the supporting' base. A

10. An arch for dam constructions having a flexible joint thereacross consisting of a Horrible material disposed inwardly of one side of the arch, and a. non-flexible. material disposed inwardly of the opposite side of the arch.

ll. An arch for dam constructions having a flexible joint thereacross consisting of a flexible material disposed inwardly of one side of the arch, a non-flexible material disposed inwardly of the opposite side of the arch, and means providing a slip joint between the fierrible and nondiexible materials of the joint.

12 An arch for dam constructions including; a flexible joint extending thereacross consistingi` of a metal diaphragm anchored in said arch on opposite sides of said joint, a flexible material disposed inwardly of one side of the arch adjacent said diaphragm, and means providing a slip joint at the opposite side. of said diaphragm from `said flexible material,

13. In an arch for dam constructions Vthe combination of a pair of arch portions separated by a joint, said joint including' a V shaped metal diaphragm anchored inwardly of the portions of the arch adjacent said joint, a fiez-cible material extending inwardly of the entrados side of said arch at one side of said diaphragm, a cementitious non-fiexi ble material anchored inwardly of the in trados side of said arch, and a strip of material providing a slip connection between the facing' surfaces of the arch portions between the non-fiexible material of the joint and said diaphragm.

let. A retaining,v arch comprising a base, an arch concave-convex portion, and a joint intermediate the base and arch portions including a waterproof sealing; material disposed inwardly of the convex side of the arch, a metal diaphragm, anchoring` the base and arch portions, and a permanent sealing material intermediate the convex and concaved sides of the arch.

15. That method of constructing arches which consists in pouring a base, providing a water proof joint coi'istruction upon said base, pouring an arch portion, and upon settling of the archl portion with respect to said base at the joint of said base and arch pord tions providing,- a permanent seal..

16. That method of' constructinn` arches for dams which consists in the pouring' of a besevl providing; a slip joint on said base, pouring an arch portion on said slip joint, and upon predetermined settling of the arch portion with respect to the base permancntlTT sealing; the joint at the base and arch port-ions.

17. That method of constructing arches for dams which consists in separately pouring' base and arch portions with a slip joint therebetween and recesses in the intrados and entrados sides of the juncture thereof, sealinga the entrados side of the arch with a waterproof flexible material,v and upon predetermined positioning of said arch portion with respect to said base permanently disposing a cementitious seal in the recess at the intrados side of said arch.

18. That methodk of constructinc,` arches for multiple arch dams which consists in pouring the base portion and major arch portions of said arch so as to leave recesses inwardly of the intrados and entrados thereof at the juncture of said base and major arch portions, said recesses extending' substantially transversely of the arch, sealinfr the entrados recess with fiexible waterproof material. subjecting` the arch to its load and at a predetermined time sealing the intrados recess with a permanent cementitious material.

19. In an arch dam, the combination of an inclined arch. and a cantilever wall supported by said dam at the top of said arch of the arch.

20. A multiple arch dam comprising piers,

A arches supported by the piers on inclined axes, and a cantilever wall supported at the top of the dam by said arches and piers and sloping upstream at right angles to the axes of the arches.

2,1. A multiple arch dam comprising piers, arches, and Walls anchored to said piers and arches at the top of said dam extending outwardly of the arches and being of least depth at the crown ofv said arches.

22. A multiple arch dain comprising a plurality of arches having the convex sides thereof facing upstream,` and a cantilever wall carried by the arches and extending substantially at right angl-cs to the axes of the arches at the tops thereof toward the upstream sides.

23. A multiple arch dam comprising a plurality of arches having the convex sides thereof facing upstream, and a wall extending substantially at right angles to the axes of` the arches at the tops `thereof toward the upstream sides, said wall having` a' horizontal top edge at its free end.

24. A dam construction comprising a plurality of hollon7 piers each including arch supporting Wallis7 a plurality of arches spanning said piers with the springing edges thereofv resti-ng upon said supporting wallss and a top wallfor saidy dam connected with said arches and side walls and extending toward the upstream side thereof at right angles to the aXes of the said arches.

A dam construction comprising a pier having spaced side walls, and an inclined Wall 'supported by said side Walls, and arches supported by said piers, each of said arches being transversely jointed intcr1ncdiatc the upper and lower portions thereof to permit relative movement of said portions on opposite sides of said joint.

26. In a multiple arch dam the combination of a pair of adjacent arches having convoi;A sides facing upstreani, said convex sides being arranged throughout the height'l of said arches to the top thereof, and a wall connected with the top portions of said arches extending at an oblique angle to the ares of said arches and sloping towards the upstream side of said arches, said wall he ing arranged between the crowns of said arches so as to be shallowest at the crowns and deepest adjacent the sninging edges ol said arches. Y

ln a` multiple arch dani the combinatien of a pair of adjacent arches having conv-ef; sides facing upstream, said convex sides being arranged throughout the height of said ar lhes to the top thereof. a wall conith the top portions of said arches neete-.fl w etendine` at an oblique angle to the axes of seid arches and extending towards the upstream side of said arches. said wall being arrwiged between the crowns of said arches so as to be shallow-est aty the rowns and dee] t adjacent the springing edges of said aes. and a buttrcss connected at thil springing edges of said arches and extending outwardly from the downstream side of .said arches.

28. In an arch dam the combination of an arch wall. and an extension formed at the upper portion of thearch 'all providing' a surface ohliqueljr arranged with respect to the axis of the arch in ovcrhanging relation with the upstream side of said arch.

VICTOR HUGO COCHRANN. 

